If you'll post a list of which /mouseto functions aren't working I'll see if I can't either fix them or add error checking to return an error message.
I tried to document the source code heavily when I worked on fixing /mouseto and /click. So did the rest of the mouse team at the time. If you look through EQLib_Mouse there is probably enough in the comments to cover almost all of what DOES work. Uncommented stuff is usually post-LDoN; I didn't make most of those changes, but that was mostly in how clicks were handled and not in the parser. The parser code is the critical bit for actually using the commands.
